\documentclass{article} 

\usepackage [ active,new,old ] { correct }  % \Add and \Del Corrections %
\usepackage{color} 
% this is a test file for my tex diffing code 
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\begin{document} 

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\section{ introduction } %
\label{intro} 

In this section, section %
\ref{intro}  we will have a block of text that we can look at in our differ to see if we can get some useable output. I need a few sentences and a few environments % this is an inline comment In this section, section %
\ref{intro}  we will have a block of text that we can look at in our differ to see if we can get some useable output. I need a few sentences and a few environments % this is an inline comment In this section, section %
\ref{intro}  we will have a block of text that we can look at in our differ to see if we can get some useable output. I need a few sentences and a few environments % this is an inline comment In this section, section %
\ref{intro}  we will have a block of text that we can look at in our differ to see if we can get some useable output. I need a few sentences and a few environments % this is an inline comment In this section, section %
\ref{intro}  we will have a block of text that we \Del{can look at in our differ to see if we can get some useable output. }\Add{look at in our differ to see if we can get some useable . some extra }I need a few sentences and a few environments % this is an inline comment 
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 $$  x^{ z }  + y^{ z }  \neq \Add{p + }z^{ 3 }  \forall z %
 $$  
That was a bit of a displayed equatiooion. 
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\end{document} 
 the diff ratio of this file is 0.949153
